The present invention relates to a method and apparatus for analyzing a regional ventricular function of a subject heart using a center line method.
2. Description of the Related Art
A proposal has been made for analyzing regional ventricular function and diagnosing the cardiac function of a subject. In particular, the center line method has generally been employed in view of its favorable clinical results. This technique is disclosed in "Diagnostic Methods-Ventricular Performance, Sheehan et al. Circulation Vol. 74, No. 2 Aug. 1986". According to this method, the heart is continuously imaged through, for example, an X-ray DF (digital fluorography) apparatus for angiography to obtain a contour image of the heart in an end diastole (ED) phase, that is an ED contour image, and a contour image of the heart in an end systole (ES) phase, that is the ES contour image. The ED and ES contour images are superimposed in a manner to align with their lines connecting the midpoint of the aortic valve to the apex. A line passing between the contour images, i.e. center line is drawn. A plurality of lines which are orthogonal to the center line are drawn at an equal interval along the center line from the ED contour image to the ES contour image. These lines are called "contraction chords" representing the extent to which the heart contracts. The length of the chords are measured to find a corresponding rate of contraction. A graph is prepared with the rate of contraction as ordinate and the number of chords along the center line as abscissa. The cardiac function graph is compared with the normal cardiac function graph to diagnose the ventricular function.
According to the aforementioned method, a cardiac function graph is prepared from the patient's cardiac contour image and the patient's cardiac function graph is compared with the normal cardiac function graph to evaluate whether or not the cardiac function of the patient falls within the standard deviation. However, it is not possible to diagnose any abnormal region in the patient's heart unless such an evaluation is initially made. That is, diagnosis cannot be made directly from the patient's cardiac contour image, failing to diagnose prompt cardiac function.